Lubricating device in compressors for refrigerators

ABSTRACT

A lubricating device in a compressor with a vertical axis for a refrigerator which includes a tube having an upper part with a circular section and a lower part whose lower end section has a spiral shape which is linked with a circular section of the upper part of the tube by means of rectilinear generatrices. The tube also has a longitudinal fissure and a paddle fixed to its central part. The tube is placed in a slanting position at the end of the crankshaft of the compressor and rotates therewith to pump oil from the sump to the parts needing lubrication while at the same time separating particles of refrigerating gas from the oil.

[ Jan. 7, 1975 lllite States Patent 11 1 Bone 3,049,285 8/1962 l84/6.l8 X

[ LUBRICATING DEVICE 1N COMPRESSORS FOR REFRIGERATORS & r k M .m nV aO 68D D u 10.0 0 a .6 e F v. m m S 6 Maw. l W60 "7 .m m m 6 ae m m Em VJ Wm Hum m o n ma PAA .m v a Dr :L, n 0 .1 1 m mr e .m P Mm P u 90 MS m B im g mE L N w n m w v .mA l 53 77 l l Mosher Italy ABSTRACT [22] Filed: Oct. 18, 1973 [.21.] Appl' 407467 A lubricating device in a com pressor with a vertical axis for a refrigerator which includes a tube having an upper part with a circular section and a lower part [30] Foreign Application Priority Data Oct. 19, i972 42916/72 whose lower end section has a spiral shape which is linked with a circular section of the upper part of the particles of refrigerating gas from the oil 26 2 70W. 3 3 a Um 0 00F 7 m 4 S m T 4 .8 N w m B E 5 6,101 MM 14 t .lP 6 0/ 4 SE 4 8 e m 1 T m 9 m m w H m Mn 6 D R E a .e M L m U I. Smfm UHF H N m 555 5 2,766,929 10/1956 Rusch et 417/372 x 3 Claims, 3 Drawing Figures LUBRICATING DEVICE IN COMPRESSORS FOR REFRIGERATORS The present invention relates to a lubricating device in compressors for refrigerators and particularly to certain improvements in a lubricating device of well known types of compressors with a vertical axis carrying, on the crankshaft end, a tube reaching the oil sump located in the lower shell section and thus conveying, by a centrifugal effect, the oil to the couplings of the compressor needing lubrication. Lubricating systems are known embodying small tubes, or purposely drilled cones, plunged into the oil sump and assembled on the crankshaft in such a way as to present the lower end of the oil feeding line centered on the rotation axis of the motor shaft to prevent any clattering in the lubricant, and the upper section of said feeding line more and more out of center with respect to said rotation axis so as to set the lubricant particles in a centrifugal motion and send them upward along the slanting walls of the tubes.

The purpose of the present invention is to improve known lubricating systems of the above-mentioned type especially as regards the head of the pumping device and the separation of the particles of the refrigerating gas mixed with the sucked lubricant.

The technical problem solved was finding of a suitable form for the suction tube in order to secure a high head to the pump and, at the same time, to favor the separation of the refrigerating gas from the lubricating oil as well as to prevent the particles from reaching the couplings to be lubricated, which particles would in fact hinder the flow of oil to the couplings located above.

The solution of the technical problem is found in the tube having an upper part with a circular section and a lower one with a final section spiral in form joining the circular section of the upper position by means of rectilinear generatrices, said special form being adapted to create, at the mouthpiece of the tube, a dynamic action on the lubricant in addition to the action caused by the centrifugal effect in the determination of the heads of said device.

Further advantages and characteristics thereof will be evidenced in the following non-limiting description ofa preferred embodiment of the present invention and in the attached drawings, in which:

FIG. It shows the lower part of the crankshaft bearing the tube of the present invention;

FIG. 2 shows a detailed vertical view of the tube of FIG. 1; and

FIG. 3 shows a partial bottom view of said tube.

In FIG. ll, shaft 110 of a known compressor is shown in a vertical position. Shaft It) ends below with crankshaft 11 and knob 12. Inside and in an axial position to knob 12, to crankshaft Ill and shaft there runs a duct 13 for the lubricant, marked with a dashed line on FIG. I, communicating with the exterior near knob 12 and shaft 110 so as to convey the oil sucked from the oil sump 14 respectively to lubricate the couplings of crankshaft knob connecting rod head and of shaft support bushing according to a technique normally employed in this field.

Set on the lower part of the crankshaft knob 12, near the lower end of duct 13, is tube 15, whose lower part is immersed in oil sump M.

With reference to FIG. 2, tube 15 consists of an upper part 16 having a circular section with a longitudinal fissure l7 and a lower part 18 with a transversal section having a variable form. From the spiral form of the lower end (FIG. 3) one passes to the circular section corresponding to the upper part 16 and these two forms of the extreme sections are linked by means of rectilinear generatrices.

Interrupted fissure l7 widens as it extends downwards owing to a tapering of part 18 of the tube 15 which, sets slantingly on knob 12, has edges 20 and 21 of the fissure positioned vertically and in line with axis 22 of shaft 10 (FIG. 1). In the central part of tube 15 is fixed a paddle 19 whose purpose will be illustrated hereinafter. Owing to the rotations of motor shaft 10, the tube rotates with its slanting axis around a vertical rotational axis 22 of shaft 10 and the particles of the lubricant contained in tube 15 will be accelerated upwards, due to the effect of centrifugal force, along the inclined wall of tube 15.

To this main pumping effect, already known, is added, in accordance with the object of the present invention, a second effect derived from the special form for part 18 of tube 15.

With reference to FIG. 3, when a particle 23 of lubricant comes into contact with the internal wall of tube 15 having a transversal section with a spiral shape the particle is subject to a dynamic action, owing to the rotation of the spiral around axis 22, which initiates a thrust of the particle 23 against the wall of tube 15. The component of thrust along the inclined wall of the tube 15 constitutes a secondary effect which is added to the main centrifugal effect and increases, to a degree, the dynamic term of the energy possessed by the particle with the consequent increase of the pump head. Fissure 17 on tube 15 has the task of separating the particles of refrigerating gas sucked with the oil, which would otherwise hinder the regular downflow of the vein of lubricant towards the spots to lubricate.

The tube 15 is placed on the shaft 10 in such a way that during rotation of the shaft the degree of eccentricity of the part affected by the fissure is less than that of the full wall of the tube itself.

The particles of refrigerating gas, being lighter than the particles of the lubricant, go toward the fissure and tend to leave the tube 15 flying upwards.

This phenomenon is favored also by the fact that in operation a part of fissure l7 occupies the depression within the rotating surface 25, which is formed by the joint action of the rotation of tube 15, and by the formation of bubbles of refrigerating gas caused by said rotation.

The rotation of the tube in the mass of the lubricant causes, in it, the formation of a rotating surface. The shape of this surface is also affected by the formation of bubbles of refrigerating gas, initiated by the clattering of the tube into the mass of lubricant which, as has been said, is mixed up with particles of refrigerating gas. It has been noticed, during tests, that owing to the special shape of the lower part of the tube 15 the axis 24 of surface 25 is slightly out of center with respect to axis 22 of the motor shaft 10 as is shown by FIG. 1, in which this detail has been enlarged.

The bubbles of refrigerating gas fly upwards inside the surface 25 lapping the external surface of tube 15. This gaseous ascension favors the formation, through fissure 117, of the particles of refrigerating gas in the tube and, at the same time, it draws, in its wake, a certain quantity of other particles of refrigerant placed near the mouthpiece of tube 15, thus avoiding their being sucked by the tube itself.

The task of paddle 19 fixed to tube 15 consists in stirring the mass of lubricating oil 14 which mixes with the gaseous refrigerant, thus forming bubbles in all the mass of oil according to a contrivance already employed in the specific field.

These bubbles reduce the possibility of the oil transmitting noise from the internal sources to the outer shell of the compressor.

What is claimed is:

1. A lubricating device in a compressor with a vertical axis for a refrigerator comprising a tube placed in a slanting position at the end of the crankshaft of the compressor and adapted to pump, by a centrifugal effect, the lubricating oil contained in the lower part of the compressor shell to the couplings to be lubricated of said compressor, said tube having an upper part with a circular section and a lower part, immersed in the lubricant, having the cross-sectional shape ofa spiral arc, in which said spiral arc, from the lower end of said tube, changes form until it becomes of circular crosssection at the lower end of said upper part, to create at the mouthpiece of the tube, a dynamic action on the lubricant in addition to the action due to the centrifugal effect in the determination of the head of the device.

2. The lubricating device of claim 1, wherein said tube has a longitudinal fissure shaped and positioned in such a way as to favor, during the rotation of the tube, the separation of the particles of refrigerating gas mixed up with the lubricant and their elimination from the inside of the tube itself.

3. The lubricating device of claim 1, wherein said tube carries, fixed in its central part, a paddle which upon rotating with the tube stirs the lubricating mass in the shell in order to favor the formation, in it, of bubbles of refrigerating gas for reducing the possibility of the oil to transmit, to the shell, the noise produced in the compressor.

* l= l =l 

1. A lubricating device in a compressor with a vertical axis for a refrigerator comprising a tube placed in a slanting position at the end of the crankshaft of the compressor and adapted to pump, by a centrifugal effect, the lubricating oil contained in the lower part of the compressor shell to the couplings to be lubricated of said compressor, said tube having an upper part with a circular section and a lower part, immersed in the lubricant, having the cross-sectional shape of a spiral arc, in which said spiral arc, from the lower end of said tube, changes form until it becomes of circular cross-section at the lower end of said upper part, to create at the mouthpiece of the tube, a dynamic action on the lubricant in addition to the action due to the centrifugal effect in the determination of the head of the device.
 2. The lubricating device of claim 1, wherein said tube has a longitudinal fissure shaped and positioned in such a way as to favor, during the rotation of the tube, the separation of the particles of refrigerating gas mixed up with the lubricant and their elimination from the inside of the tube itself.
 3. The lubricating device of claim 1, wherein said tube carries, fixed in its central part, a paddle which upon rotating with the tube stirs the lubricating mass in the shell in order to favor the formation, in it, of bubbles of refrigerating gas for reducing the possibility of the oil to transmit, to the shell, the noise produced in the compressor. 